3 3/4 c. sifted flour
1/2 tsp. salt
1/2 tsp. baking soda
3 tsp. baking powder
1 c. shortening
3 tbsp. grated grapefruit rind
2 1/2 c. sugar
4 eggs
1 egg yolk
3/4 c. grapefruit juice

Sift flour, salt, soda, and baking powder together. Cream shortening with grapefruit rind and sugar until fluffy. Add whole eggs and yolk, one at a time. Add sifted dry ingredients alternately with juice in small amounts; beat well after each addition. Pour into 3 (9 inch) cake pans. Bake at 350 degrees for 30 to 35 minutes. Ice when cool.